Manufacture of industrial objects from volcanic or other fusible rock.



UNITED STATES PATENT OFFICE.

FRANCOIS BIIBBE, OF MAURIAC, MOE.

MANUFACTURE OF INDUSTRIAL OBJECTS FROM VOLCAN IC OR OTHER FUSIIBLE ROCK.

No Drawing.

Specification. of Letters Patent.

Application filed July 13, 1911.

Patented Aug. 18, 1914. Serial No. 638,815.

To all whom it may concern:

Be it known t at I, FRANQOIS Rmnn, a citizen of the Republic of France, residin at 26 Avenue de la Gare, Mauriac, Cantu, in the Republic of France, have invented certain new and useful Improvements in the Manufacture of Industrial Objects from Volcanic or other Fusible Rock, of which minerals by melting and molding said rocks or mineral, the distinction being due to the fact that the rocks or minerals are, after fusion and molding, but before their temperature falls below 500 0., placed in a reheating furnace, heated to about 800 C. and remain in this temperature from half an hour to an hour and a half according to the size of the object, and are then cooled very gradually. The prolonged action of the high temperature has the effect of devitrifying the substances cast, by which they acquire advantageous qualities, princlpally reat strength and toughness. However, this action is only effective if the sub- .stances to be operated upon have high melting points and are otherwise suitable, for example basalt, lava, trachyte, etc.; but with too easily fusible substances like scoria, slag, etc., the present process does not give good results from the point of view of resistance of the 1products.

Basa t is typical of the volcanic rocks and will be given in the following descri tion as an example of the substances treate This rock, which melts .between 880 and 1300 C. according to the variety thereof, is melted in any suitable furnace capable of producing the requisite temperature. it can then be brought to a spon y state similar to umice stone by one of t e three methods ereinafter given by way of examples, or it can ded or fashioned by a fourth method First method.

The substance in a semi-fluid state is placed in a heated receptacle of preferably tall shape and of which the bottom is provided with numerous and very fine twyers through which a gas at a high temperature and at a convenient pressure is introduced. Part of the gas escapes but art remains in the mass in the form of bub les which puif up the mass. Cast-in is done when the increase in volume of the mass is judged sufficient.

Instead of perforating the bottom of the receptacle, quartz or other pipes can be used which do not fuse at the temperatures employed and which can be in the form of very fine twyers by which the gas is introduced lnto the mass as above described. The basalt can be run in a state of fusion into a tall receptacle maintained at a suitable temperature and provided along all its height with pipes similar to those above described and arranged in quincunx in horizontal rows and through which the gas is introduced into the mass. The mass flows past the tubes and escapes at the bottom, of the receptacle therin its assage. The ubbles rawn b of t e mass can in this method onl burst on the surface.

' Second method.

To the mass in fusion coming from the furnace is added from about 1} to 5% of a the flow y slightly fresh bubbles in.

pulverized substance capable at the given temperature of producin numerous gaseous molecules of steam or ot er as in the mass or which can decompose wit out explosion in producing) a gas. Among suitable substances are asa t itself (which should be slightly heated) carbonate of lime, bicarbonate of soda, gypsum, sawdust, carbon, graphite, etc.; the substance added is mixed quickly and as evenly as possible with the mass. The action of the pulverized basalt, like that of the other pulverized inert bodies, is a result of the disengagement of the air stored up between the particles of the pulverized matter. It should not be stirred very-long so as not to facilitate the esca of the bubbles. The gas 'ven off by th: mixture of graphite and casion with melted basalt is the result of the reducing action of the carbon on the oxid of iron contained in the basalt, the oxid of iron being reduced by the carbon and the carbonic acid given off according to the well known reaction. The gaseous bubbles are for the most part retained in the basaltic bath and produce a" ner in which the mixing has been efiected. Sawdust produces large bubbles; bicarbonate of soda gives smaller bubbles.

The operation can be made in any'heated receptacle suitable for receiving basalt in fusion and if necessary it can be done in the mold itself. The. following method is more simple: The basalt is melted either in a crucible of commercial plumba 'o, or in a furnace lined with plates or briclrs of plum--' iron, steel, earth, earthenware, iron plate or other molds can be used. With the exception of those, of iron plate, the molds shouldbe heated to about 600 C. They are'best' made of severalpieces to facilitate removal of the cast. 7

Fourth method.

Instead of being made of porous basalt} certain articles can be made of solid basalt,

lightened by one or more spaces. These spaces can be formed when castin by using suitable cores. Certain hollow ob ects could even be blown, similar to glass.' Further certain objects requiring great resistant qualities can be obtained by casting in solid basalt Without spaces.

AnneaZz'ng.The formed objects should be placed in a reheatin furnace otherwise their exterior partsra idly cool and become vitreous; the core on y would be devitrified and take the properties of the rock. If the object were very rapidly cooled it would break spontaneously. The objects are placed in the reheating furnace either immediatelyafter they are set in the mold or i'mmediatey after the consistency of the material is su cient if they should be removed from the molds before baking; in all cases the articles are placed in the reheating furnace before their temperature falls below about 500 .C.

. If solid vitreous basalt articles are required the temperature is allowed to rapidly fall to about 600 C. the remainder of the cool- ,ing process being slow and gradual. The

temperature of the reheating furnace for objects to be completely devitrified is maintained at about 800 0. Below about 700 C. devitrification would not be produced; above 900 the object would take a somedevitrificationbeing finished the objects are cooled gradually and slowly as in glass making. It is advisable to take care that the parts of each object are exposed to temperatures as near as possible equal at a given moment, this being particularly true of objects of lar e size. I

All the o jects are covered with a glaze varying in color according to the reheating temperature, particularly from the manner inwhich they-have been first attacked by i this temperature. Bronze, bluish and violet colors are the most ordinary.

The described treatment of basalt is ap- ..plicable to other rocks of volcanic origin,

to the lavas of Auvergne in particular. Certain modern igneous rocks obsidians for example, disengage suddenly at the melting temperature, a great quantity of gas-sometimes giving rise toa veritable explosion. Mixed with other rocks in a small proportionitgives to the entire mass a very marked porous state. Several ofthesesubstances can be used for forming a single object, someforming the core and others the outer surface, the said core being either-a porous or full mass. v

N onfusible and various objectscapable of supporting high temperatures can be given a covering of cast basalt, this covering can be total or partial and can be thick or reduced to a sim le layer, but it is necessary that the coe cients of expansion of the two bodies are approximately the same.

Sand, silicious gravels, carborundum and other substances can be incorporated with basalt in'the manufacture of certain objects for example paving stone.

Basalt initially vitrified and then devitrified by reheatinghas mu'chgreater resistance to wear an'dis of-greater hardness than basalt devitrifiedin the first instance, so that in the first case basalt can be used for the manufacture of grindstones, either pure or with the addition of carborundum, for example. Colorants or decolorants as used in the manufacture of glass can be added to the fused mass to modify the colors; in some cases the objects made can be coated with artificial enamel. Further in the process where gaseous insufliation is used a gas,

' thereto.

can be selected which would chemically act on the natural colorants of the different rocks so as to modify the neral color.

The property which me ted basalt has of adhering to iron when the latter is brought to a temperature of about 1000 C. can be utilized for making objects of armored basalt. I

The elasticit of the substance, especially when porous, a lowsit to expand or contract without ceasing to adhere with the metal The new products hereinbefore described are both light .and very resistant, unalterable and impenetrable by damp, are bad conductors of not attacked by acids, are molded aseasily as plasterand are harder than marble.

They are suitable for many applications.-

For instance they-can be made into simple molded or carved building stones, guttering, fiagstones, tables, tiles, grindstones, pulleys, connecting plates, basins, bricks, cornices, various pipes, insulators, columns vases, many ob ects of art, knobs, door andles, curbstones,-vessels, railway sleepers and varioulsother objects too numerous to mention.

aims:

1. The method hereinbefore described for" the manufacture of objects made of molten stone which consists in melting basalt, in casting the objects from the melted mass placing such objects, before their temperatures has fallen below 500 centigrade, in a reheating oven at a temperature of about 800 centigrade, in maintaining the said objects at the last named temperature until such objects are completely devitrified and in cooling the said objects very slowly.

2. The method hereinbefore described for the manufacture of objects made of molten stone which consists in melting basalt, in subjecting the mass thus melted to the action of a body capable of producing bubbles in v casting the objects from the said mass thus sound, heat and electricity, are

rendered porou in placing the objects thus melted, before t eir temperature has fallen below 500 centigrade in a reheati oven at a temperature of about 800 centigrade, in maintaining the said objects at the last named temperature until such objects are completely devitrified and in cooling the said objects very slowly.

3. The hereiniefore' described method for the manufacturfi of objects made of molten stone which consists in melting basalt, in subjecting the mass of molten basalt to the contact of carbon for the purpose of giving off gases therein which renders such mass porous in casting the objects from the said mass thus rendered orou's, in placing the objects thus cast, be ore their temperature has fallen below 500 centigrade, in a reheating oven at a temperature of about 800 centigrade, in maintaining the said objects at the last named temperature until such objects are completely devitrified and in cooling the said objects very slowly.

4. The hereinbefore described method for the manufacture of objects made of molten stonewhich consists in melting basalt on a hearth of carbonaceous material for the purpose of giving off gases therein which jects from the mass thus rendered porous, in placing the objects thus cast, before their temperature has fallen below 500 centigrade in a reheating oven at a temperature of about 800 centigrade, in maintaining the said objects at the last named temperature until such objects are completely devitrified and in cooling the said objects very slowly.

In testimony, that I claim the foregoing as my invention, I havesigned my name 1n presence of two subscribing witnesses.

'FRANQOIS RIBBE. Witnesses:

DEAN B. Mason, MAURICE Roux.

renders 'such mass porous, in casting ob 

